[Commit-gnuradio] gr-error-correcting-codes/src/lib gr_streams_en...

[Michael Dickens]

CVSROOT:        /sources/gnuradio
Module name:    gr-error-correcting-codes
Changes by:     Michael Dickens <michaelld>     06/07/14 15:49:54

Modified files:
        src/lib        : gr_streams_encode_convolutional.cc 
        src/lib/libecc : encoder_convolutional.cc 

Log message:
        Added debugging comments to the gr-block;
        Tweaked the feedback copying to mask off the LSB (&1), since its
        absence is required for the feedback computations.

CVSWeb URLs:
http://cvs.savannah.gnu.org/viewcvs/gr-error-correcting-codes/src/lib/gr_streams_encode_convolutional.cc?cvsroot=gnuradio&r1=1.3&r2=1.4
http://cvs.savannah.gnu.org/viewcvs/gr-error-correcting-codes/src/lib/libecc/encoder_convolutional.cc?cvsroot=gnuradio&r1=1.6&r2=1.7

Patches:
Index: gr_streams_encode_convolutional.cc
===================================================================
RCS file: 
/sources/gnuradio/gr-error-correcting-codes/src/lib/gr_streams_encode_convolutional.cc,v
retrieving revision 1.3
retrieving revision 1.4
diff -u -b -r1.3 -r1.4
--- gr_streams_encode_convolutional.cc  9 Jul 2006 21:02:44 -0000       1.3
+++ gr_streams_encode_convolutional.cc  14 Jul 2006 15:49:54 -0000      1.4
@@ -130,6 +130,8 @@
 (int n_code_inputs,
  int n_code_outputs)
 {
+  fprintf (stderr, "gr_s_e_c: d_encoder == %X\n", (unsigned int)d_encoder);
+
   // create the correct input signature; 1 bit per input char
 
   set_input_signature (gr_make_io_signature (n_code_inputs,
@@ -142,40 +144,38 @@
                                              n_code_outputs,
                                              sizeof (char)));
 
-// set the output multiple to 1 item, then let the encoder class
-// handle the rest internally
+  // no need to set the output multiple (to 1 item), since 1 is the
+  // default, and the encoder class handles the rest internally
 
-  set_output_multiple (1);
+  // no need to set the relative rate (# out / # in) because for each
+  // input bit per input stream there is 1 output bit per output
+  // stream ... with a little added for termination, but ignore those.
 }
 
 gr_streams_encode_convolutional::~gr_streams_encode_convolutional
 ()
 {
   delete d_encoder;
+  d_encoder = 0;
 }
 
 /*
- * Compute the number of input bits (items in this case, since each
- * item has 1 bit in it) needed to produce 'n_output' bits (items in
- * this case, since each item has 1 bit in it).
- *
- * For convolutional encoders, there is 1 bit output per bit input per
- * stream, with the addition of a some bits for trellis termination if
- * selected.  Thus the input:output bit ratio will be:
- * 
- * if (streaming | no termination), 1:1
- *
- * if (not streaming & termination), roughly 1:(1+X), where "X" is the
- * total memory size of the code divided by the block length in bits.
- * But this also depends on the state of the FSM ... how many bits are
- * left before termination.
+ * Compute the number of input items needed to produce 'n_output'
+ * bits.  Handled internally by the encoder.
  */
 
 void gr_streams_encode_convolutional::forecast
 (int noutput_items,
  gr_vector_int &ninput_items_required)
 {
+  fprintf (stderr, "gr_s_e_c::forecast: #out = %d\n",
+         noutput_items);
+
   int ninput_items = d_encoder->compute_n_input_bits (noutput_items);
+
+  fprintf (stderr, "s_e_c::forecast: #out = %d, #in = %d\n",
+         noutput_items, ninput_items);
+
   size_t ninputs = ninput_items_required.size();
   for (size_t n = 0; n < ninputs; n++)
     ninput_items_required[n] = ninput_items;
@@ -188,12 +188,18 @@
  gr_vector_const_void_star &input_items,
  gr_vector_void_star &output_items)
 {
+  fprintf (stderr, "gr_s_e_c::general_work: Starting #out = %d\n",
+          noutput_items);
+
   // FIXME: compute the actual number of output items (1 bit char's) created.
 
   size_t t_n_input_items = d_encoder->compute_n_input_bits (noutput_items);
+
+#if 0
   size_t t_n_output_items = d_encoder->compute_n_output_bits (t_n_input_items);
 
   assert (t_n_output_items == ((size_t)noutput_items));
+#endif
 
   // "work" is handled by the encoder; which returns the actual number
   // of input items (1-bit char's) used.
@@ -202,6 +208,8 @@
                                       (char **)(&output_items[0]),
                                       (size_t) noutput_items);
 
+  assert (0);
+
   // consume the number of used input items on all input streams
 
   consume_each (t_n_input_items);

Index: libecc/encoder_convolutional.cc
===================================================================
RCS file: 
/sources/gnuradio/gr-error-correcting-codes/src/lib/libecc/encoder_convolutional.cc,v
retrieving revision 1.6
retrieving revision 1.7
diff -u -b -r1.6 -r1.7
--- libecc/encoder_convolutional.cc     12 Jul 2006 23:43:38 -0000      1.6
+++ libecc/encoder_convolutional.cc     14 Jul 2006 15:49:54 -0000      1.7
@@ -411,9 +411,12 @@
       std::cout << "\n";
     }
 
-    // get the FB code, and OR with 1 to make sure it's valid
+    // get the FB code; AND off the LSB for correct functionality
+    // during internal computations.
 
-    t_in_code = ((*code_feedback)[maio(m,n)]) | 1;
+
+    t_in_code = ((memory_t)((*code_feedback)[maio(m,n)]));
+    t_in_code &= ((memory_t)(-2));
 
     // find the memory requirement